An abandoned anthracite coal mine turned museum outside Hazleton, Luzerne County, PA. | Photo: iStock/New_Folder
A lifetime ago in May 2016, in the midst of the Republican presidential primary, I wrote about Pennsyltucky in three dimensions: urban/rural split, household income, and politics. In that piece I described the Commonwealth of Pennsylvania’s political battleground as the Philadelphia suburbs—though the city and its near-suburbs reliably voted Democratic. 
Pennsyltucky reliably voted Republican while both the Lehigh and Wyoming Valleys in the northeast voted reliably Democratic along with the far northwest county of Erie, home to the county’s eponymous and the state’s fourth-largest city, and Allegheny County, home to the state’s second-largest city of Pittsburgh.
Then in November 2016 Pennsylvania voted.
Prior to 2016 the state had voted Democratic in six consecutive presidential elections over 24 years—almost an entire generation. Then Donald Trump won the state by fewer than 45,000 votes. So what happened? How did the Democrats’ blue wall crumble so suddenly in Pennsylvania? Four years on—and before we vote again in the November 2020 election—we need to reevaluate the Commonwealth’s political geography, because a new Pennsylvania political geography is emerging. Welcome to Trump’s woods, or Trumpsylvania.
For decades, pundits have considered Pennsylvania a swing state, a battleground state, a purple state. With its geography oriented primarily east to west, Pennsylvania stretches across three distinct regions of the country and in 1986 James Carville famously described the state’s geography thusly:
“Between Paoli and Penn Hills, Pennsylvania is Alabama without the Blacks.”
34 years later, the quote has evolved and the named suburban towns have been replaced by their respective metropoles, Philadelphia and Pittsburgh. Four years ago I focused on that Alabama in the middle of the state, Pennsyltucky. Geographically it is the state’s largest region, centred on the Appalachian Mountains and shaped like a T. It runs east to west across the northern tier of the state and then north to south down the centre of the state roughly along the west bank of the Susquehanna River to the border with Maryland. West of Pennsyltucky, Pittsburgh and Erie connect to the Midwest and Great Lakes while, to the east, the nation’s sixth-largest city, Philadelphia, and the Delaware Valley integrate with the Northeast and Mid-Atlantic.
If we want to understand Pennsylvania’s changing political geography in 2020, we need to look beyond the red hinterlands of Pennsyltucky that I explored four years ago to the rest of the Commonwealth. And to understand the present, we need to look to the past.
Since 1976, Democrats have reliably won Philadelphia; the northeastern Coal Region around the Wyoming Valley’s Lackawanna and Luzerne counties, with Carbon County occasionally voting Democratic; and the western and southwest counties surrounding Allegheny County, home of Pittsburgh. Mining, manufacturing, and steel powered their local economies. Organised labour had deep roots, with sometimes violent histories against Republican business interests. In the northeast, for example, the Molly Maguires agitated for improved working conditions and workers’ rights. If nothing else, these were dyed blue in the spun and woven wool union counties.
During the 1980s and 1990s, Pennsylvania supported pro-life Democrats like Governor Bob Casey, Sr. and pro-choice Republicans like Governor Tom Ridge. In 1980 Ronald Reagan campaigned against not just Jimmy Carter but a liberal Republican, John Anderson, who ran as an independent. On cultural issues, Reagan held more conservative positions than many contemporary Pennsylvania Republicans and Anderson’s quixotic run initially garnered significant support. While Anderson ultimately lost, he won nearly 6.5% of the vote in Pennsylvania—still the largest third-party share since 1976 aside from Ross Perot.
Reagan’s victory in 1980 and again in 1984 ushered in a new, more culturally conservative Republican Party that began to take root across the United States, a party that initially sat at odds with Pennsylvania’s own political alignment. This Reagan Revolution resulted in the emergence of Reagan Democrats in southwestern and northeastern Pennsylvania. They self-identified and registered as Democrats, but voted in limited numbers for Reagan then George HW Bush because they aligned with newly Republican conservative positions on cultural issues despite their economically divergent beliefs. But even with the emergence of Reagan Democrats, Pennsylvania’s political map remained relatively stable and largely unchanged.
Then in 1992 the state and the nation elected Bill Clinton, a southern and more centrist Democrat, by a large and geographically wide margin. When it came to certain cultural issues, Clinton triangulated a third way, charting a moderate course between the right and the left. On abortion, for example, he found a winning approach by famously taking the position abortions should be “safe, legal, and rare”. Four years later Clinton won Pennsylvania again, by a slightly larger margin. He had buttressed and reinforced the Democrats’ blue wall against the rising red sea of Reagan’s Revolution. Yet 1996 would come to be the high-water mark for the Democrats' geographic footprint in Pennsylvania.
After eight years of Bill Clinton’s Third Way, the compassionate conservatism of George W. Bush defeated a more centrist John McCain in the 2000 Republican primary. While Bush beat his Democratic opponent Al Gore in the Electoral College, he lost Pennsylvania, though he halved the Democrats’ margin of victory in the state from 1996. Four years later, Bush again lost Pennsylvania—this time to John Kerry—but he succeeded again in halving Democrats’ margins. The Great Recession of 2008 wrecked support for Republicans and Barack Obama won Pennsylvania by the largest state margin since 1976. During his reelection in 2012, however, his support halved despite beating Mitt Romney. And just four years later, when Hillary Clinton ran against Republican Donald Trump in 2016, that Democratic margin of victory disappeared entirely as the Democrats lost by the narrowest of margins—0.7 points or fewer than 45,000 votes. But if we look at the margins for Democrats in presidential elections since 1992, the trend is clear.
What happened in 2016? How did the Democrats lose, albeit narrowly, to the Republicans? If we look at the geography of the county winners since 1996, we can see a lot less blue in the southwest corner of the state. In fact Hillary Clinton won only three counties west of the Delaware Valley: Allegheny, home of Pittsburgh; Dauphin, home of Harrisburg; and Centre, home to Pennsylvania State University. Reagan Democrats call those southwestern—and some northeastern—counties home.
Those maps show the results as winner-take-all. What happens if we look more closely at the results? We can look at each county by the winning candidate’s margin of victory compared to each party’s relative advantage in voter registration, i.e. how voters politically self-identify. In the graphic below we have Trump’s margin of victory to the right, Clinton’s to the left, and towards the centre we find the most competitive counties in the state. Vertically, as you move towards the top you have counties with a greater Republican advantage in voter registration, measured as a share of all registered voters in the county. Conversely, at the bottom Democrats enjoy the advantage. Counties with fairly even party mixes cluster near the centre. From this we create four distinct quadrants: in the upper-right we have self-identified Republican counties that voted for Trump; in the lower-left we have self-identified Democratic counties that voted for Clinton; in the upper-left we have self-identified Republican counties that voted for Clinton; and in the lower-right we have self-identified Democratic counties that voted for Trump.
In 1996 almost all the counties in the lower-right square voted for Bill Clinton. This includes counties in the southwest, e.g. Beaver, Erie, Westmoreland, but also counties in the northeast, e.g. Luzerne and Northampton. There are some exceptions. For example, Berks, despite its Democratic registration advantage in 2016 voted Republican, and had in every presidential election since 1976 except 2008. On the other side, Chester County had also voted Republican since 1976, except in 2008, and despite its Republican advantage, the county flipped to the Democrats.
Compare those counties to those of Pennsyltucky, the “T” of the state. Fulton, Trump’s largest margin win, and Bedford share a border with Maryland in the south of the state while Potter borders New York up north. Perry and Snyder sit along the Susquehanna River in the centre of the state. All feature not just large margins of victory for Trump (larger than any county in the lower-right quadrant), but also large Republican advantages in voter registration. Pennsyltucky, however, has consistently voted Republican and its counties are generally small and rural.
No, the key to Trump’s 2016 victory, the final breach of the blue wall, occurred in those counties in the lower-right quadrant. These are not all small rural counties—though some are. Some are old coal and steel counties like Beaver, Cambria, Erie, Luzerne, and Northampton. These are counties with hundreds of thousands of voters who ate into the usually large enough margins of Philadelphia and Pittsburgh.
What happened in 2016 is clear. Trump narrowly won a number of larger, traditionally Democratic counties. But why? To understand that we need to look at the evolution of Pennsylvania’s political geography.
67 counties comprise the Commonwealth of Pennsylvania and some like Fulton are low in population and reliably Republican. Others like Philadelphia County are among the largest in the nation and reliably Democratic. And in fact both Philadelphia and Pittsburgh are both so solidly blue and so large that Democratic candidates could afford blowout losses in the rural counties of Pennsyltucky. That still leaves 65 counties, and we can loosely group them into six different regions for our analysis. We have established Pennsyltucky and the two main cities of the state as two separate groups. The rest we can define thusly.
We looked at the 2016 Democratic/Republican party registration advantage vs. the Trump/Clinton margin of victory. But what happens if we extend that analysis back in time, say to 2000? Well, we can plot how counties voted in 2000 and connect those to their 2016 votes across the same four quadrants.
When we look at the cities and Pennsyltucky, we see that, to some extent, not much changed. Since Pennsyltucky consists of numerous counties, I labelled only a few here, but by and large between 2000 and 2016 these Republican counties became more Republican. There were, of course, some exceptions. Centre County became more Democratic, though as the home of Pennsylvania State University, that might not be surprising. Elk County, another example, remained nominally Democratic despite voting Republican. Another exception is Union County, which the first graphic showed as solidly Trump-backing in 2016. But, and with so many counties above it is hard to see, the county moved significantly to the lower-left, meaning the Republican party advantage fell and their candidates’ margin of victory shrank as well. Though at 20 point margins and a 20% advantage, it’s not likely to shift into the Democratic column in 2020 barring a massive Democratic wave.
For years the media focused on whether or not Democrats could win Philadelphia’s suburban counties: Bucks, Chester, Delaware, and Montgomery. Between 2000 and 2016, however, all four changed from counties with solid Republican registration advantages to, as a group, a slight overall Democratic advantage. Chester County remained nominally Republican, though Clinton won the county by almost 10 points. By 2016 both Delaware and Montgomery counties featured Democratic registration advantages and both voted for Clinton. Bucks is perhaps the most interesting as it was the most competitive. The county split almost evenly between Republicans and Democrats in registration and gave Democrats their second narrowest victory at 0.78 points—Trump won the state by 0.71 points. Clearly through 2016 these four counties trended Democratic.
In the Southwest we had the opposite story. In 2000, several counties still voted by narrow margins for Al Gore, but by 2016 they swung decisively to Trump and the Republican Party. Erie County, home of the state’s fourth largest city, could possibly swing back to the Democrats in 2020 if the state overall swings back. But it is hard to imagine any of the other counties swinging so far back they go blue. However, these counties’ populations are roughly similar to Philadelphia’s suburbs, so Joe Biden must significantly cut into Trump's 2016 margins to win the state.
If the Philadelphia suburbs were the expected battlegrounds in 2016 and 2012, Northeastern Pennsylvania became the new battleground in 2016. In some ways these counties resembled the Southwest—between 2000 and 2016 Republican margins of victory moved to the right, and counties like Luzerne and Carbon became Republican red. But there are several critical differences. In Southwestern Pennsylvania, the Democratic registration advantage significantly eroded as counties moved not just to the right but also up in the chart, but in the Northeast over the same timeframe we saw similar rightward movement, but very little movement up. Consequently, in the Northeast Republicans may have won elections, but voters still considered themselves Democrats. In contrast, Southwest voters by 2016 began to re-identify themselves as Republicans. And in Lehigh and Monroe counties, Democrats decidedly increased their advantage. To the region’s battleground status, all this movement placed four counties within a five-point margin for either candidate: Lackawanna (home to Scranton), Lehigh (Allentown) and Monroe (no large city) counties voted for Clinton while Northampton (Bethlehem) voted for Trump. Unlike the southwest, while a number of these counties trended Republican they largely kept their nominal affiliations with the Democratic Party. This contributed to the region’s transformation into the state’s new battleground as evidenced by the split votes and competitive results.
South Central Pennsylvania, home of the Amish, Pennsylvania Dutch, and Mennonites, presents the most interesting future. In 2000 these were among the most reliably Republican red counties in the state. In party registration, Lancaster County had the second greatest advantage for Republicans after only Snyder County, a deep red Pennsyltucky county. Between 2000 and 2016, that advantage decreased by almost 20 percentage points. Cumberland County moved similarly by 10 percentage points. Despite that movement, in 2016 Republicans in both counties enjoyed 20 percentage point registration advantages as well as 20 point margins victories over Democrats. But the region was not all solidly Republican. Berks has long been a competitive county, within a five-point margin of victory in both 2000 and 2016. York and Lebanon counties moved only slightly, becoming redder in vote, but slightly less in registration. Only Dauphin County, home to Harrisburg on the east bank of the Susquehanna River, moved from being a Republican county with Republican victories in 2000 to being a Democratic county with a Democratic victory in 2016. With large rural and exurban areas these counties remain fertile grounds for large Republican margins, but as we will see these counties are also home to small but rapidly (at least for slow-growing Pennsylvania) growing cities trending Democratic. Except for Berks and Dauphin, South Central Pennsylvania will not likely be contestable for Democrats in 2020 outside of a wave or landslide election. However, if these trends continue, it’s possible places like Cumberland and Lancaster could become Democratic targets in the long-term.
When you put those regions together, you see that numerous regions and counties prior to 2016 had been trending Republican. But critically, in 2016 Trump pushed enough of the Northeast in particular sufficiently to the right to negate Democratic votes elsewhere in the state. What were Democratic-leaning counties in the 1990s and early 2000s, places like Carbon, Luzerne, and Northampton, became solidly Republican. Meanwhile solidly Democratic counties like Lackawanna became just Democratic-leaning. Democrats, however, by 2016 had managed to only turn fewer Republican counties into contestable battlegrounds. In a normal 2020, Republicans might not expect to win Chester, Delaware, and Bucks counties, but they could make a serious run and try to limit the Democratic margins. And in places like Erie and Lackawanna, the rightward drift might push them into the Republican column as Carbon, Luzerne, and Northampton did in 2016.
A large reason for this comes down to the demographics that comprise Trump’s political base. He depends upon and courts fervent support from the white population without a university degree (and typically older as well). Contrast this to previous Republican candidates who targeted the state’s university educated, suburban white population. For example, earlier we mentioned pro-life Republican former Governor Tom Ridge; he has formally endorsed Joe Biden in 2020. When we look at Pennsylvania’s demographics, we see Trump’s attempt to win over large swathes of Pennsylvania was successful in 2016, albeit barely, because his base and the state’s demographics overlap significantly.
In a normal year, these trends would point to Pennsylvania becoming an even redder state than it was in 2016 and the red sea would finally wash away the last vestiges of the blue wall. Trumpsylvania would emerge and the old political geography would rupture entirely. Of course, 2020 has been anything but a normal year. While polls fluctuated throughout early 2020, of late they have fairly consistently given Joe Biden between a 5- and 10-point advantage. If those kinds of numbers hold, a number of the counties above would likely swing sufficiently to the left of their 2016 numbers that they would (or at least could) vote Democratic. In 2008, and to a lesser extent 2012, we saw how Barack Obama delayed the red sea change amid the Great Recession. Could a 2020 Democratic victory—if it were to happen—be a similar interruption? Could a 2020 Democratic victory disrupt likely increasingly large Republican victories? Could a 2020 Democratic victory delay the arrival of Trumpsylvania? In the short term, perhaps.
The wildcard in 2020 is that wave or landslide elections tend to place numerous places in play that would not normally be. Voters in Berks County, for example, have voted Democratic only once since 1976 when in 2008 Obama defeated John McCain by seven points nationally—not quite a landslide (double-digit margins) but a significant victory nonetheless. Early- to mid-October 2020 polling places Joe Biden ahead of Donald Trump by between 5- and 10- points, not a landslide, but in a position similar to Obama’s 2008 victory. In that scenario I expect counties like Berks, Erie, Lackawanna, and Northampton to lean Democratic or at least remain competitive. In a blowout, Luzerne likely becomes competitive. And if the bottom for Trump truly falls out, you may see some surprises like competitive Cumberland and Lancaster counties.
For our purposes, however, we want to explore the trends in the context of a “normal” election environment, i.e. an election without a global pandemic infecting millions of Americans and killing hundreds of thousands, without the worst economic contraction since the Great Depression, and without a movement for racial justice sparked by a summer of police brutality. It is quite possible, some would argue likely, that these will be sufficient push factors driving a Pennsylvania electorate inclined to vote Trump/Republican to vote for Biden and the Democrats. In other words, imagine the political conversation we were having in early January rather than now in early October.
We start with party registration. As we have seen in both Southwest and Northeast Pennsylvania, party registration does not guarantee a party victory in an electoral contest. But what we see in 2020, using data as of 5 October, should nonetheless concern Democrats. Statewide, over the last four years Democrats’ share of voters fell by 1.5 percentage points whilst Republicans’ share rose by one point and non-affiliated and third party shares collectively rose by half a point. Numerically, however, Democrats maintain an advantage of nearly 720,000 registered voters over Republicans.
But how is this Democratic decline playing out across the state’s geography? Did Trump’s election four years ago change the state political dynamics? Not really, if we look at the same county-level breakdowns as we did earlier, we see how, if anything, the 2016 election simply accelerated the state’s red shift.
We plot the change in registered Democrats and Republicans. To the right of zero we have counties where Republican voter rolls are growing, to the left they are losing members. Similarly, vertically above zero we have counties gaining Democrats while below are counties losing Democrats. Along a 45º axis through the upper-right and lower-left quadrants we have a line where the parties are gaining/losing voters in equal numbers. To the line’s right, Republicans are gaining/losing more and to the left, Democrats are gaining/losing more.
The cities and Pennsyltucky present the fewest surprises. In the lower-right quadrant of the chart we have counties where Republicans are gaining registered voters and Democrats losing voters. The small populations and thus small changes in party registration makes labelling all the Pennsyltucky counties difficult, but the trend is clear. Pennsyltucky was already red and it is only getting redder. In fact only two counties in Pennsyltucky saw Republicans lose registered voters. Huntingdon, which is all but on the borderline, but also Centre County. As the home of Pennsylvania State University, I suspect the nearly equal losses in terms of registered Democrats and Republicans owes more to the pandemic shutting down universities than it does any broader political realignment. Though that can certainly mean typically left-leaning votes in college towns could be moved to the voters’ hometowns. It is also worth noting that both Philadelphia and Pittsburgh have lost registered Democrats over the last four years. Though in neither county is the difference nearly enough to flip the counties’ votes. But for their size, they are also gaining very few Republicans. It could point to a rising number of independents and/or third party registered voters.
In Philadelphia’s suburbs, Democrats have picked up tens of thousands of newly registered Democrats with Republicans losing members in every county but Bucks. As I noted earlier, Bucks could likely be one of the most competitive counties in 2020 as in 2016 voters narrowly chose Clinton over Trump. On the 45º axis we see a line where both parties make equal gains (or losses) in a county and Bucks falls just to the Democratic side.
Republicans in the Southwest have continued to entrench themselves. In all but two counties, Republicans gained members whilst Democrats lost them. In only Erie and Butler did Democrats pick up any new members. Erie could be one of the counties Democrats look to win back from Republicans, but these numbers make it more difficult unless there is a broader swing by a large margin.
And in Northeastern Pennsylvania, we see the 2000–2016 trend continuing. In several counties, most importantly Lehigh, Monroe, and to a lesser extent Northampton, we have seen nearly equal gains between Republicans and Democrats. Unlike Bucks County in the Philadelphia suburbs, however, these counties fall on the Republican-leaning side of the equal gains line. Given each of those three counties was won by less than five points, these numbers point towards a close race in a normal 2020. However, we also have the story of the Coal Region in Lackawanna and Luzerne counties. In 2016, Luzerne swung hard to the right and party registrations over the last four years have shown no signs of that trend abating. And in Lackawanna, a narrow victory for Democrats in 2016, we see a large swing to the Republicans in party registration. Democrats, of course, hope that Biden’s hometown roots can win them back some of those voters. But in a normal year with an out-of-state candidate, it would be difficult to see Lackawanna remaining blue on the election map. The other counties, which had by 2016 begun to swing to the right all continued on that track. Carbon, Columbia, and Schuylkill now appear to be firmly Republican. Wayne and Pike counties have seen less of a shift, but they were already solidly Republican and it’s difficult to see them shifting back to the Democrats in 2020, again barring a landslide-like election that drags every county to the left.
Finally in South Central Pennsylvania we see the best long-term opportunities for Democrats. In this region we see two distinct patterns over the last four years. In cases like Berks and York, to a lesser extent Adams, we have counties shedding their registered Democratic voters and picking up nearly three times as many Republicans. Berks County, which Trump won by approximately 10 points in 2016 looks to be even more Republican in 2020. But in 2008, when Obama beat McCain by 7 points nationally, Berks swung to the left for the first and only time since 1976. As clerks tally mail-in ballots in the days after Election Day, I’ll be looking at Berks for indications of a potential large-margin victory for Biden, something the latest statewide polls indicate as a potential outcome. The other trend concerns Cumberland, Dauphin, and Lancaster County. Dauphin, a narrow Clinton victory in 2016, looks to be more solidly Democratic in 2020. But Cumberland and Lancaster, which have been following the same trend of transitioning to Democratic-leaning counties, are still adding both Democrats and Republicans to their party rolls. But they are further distant from that line of equal gains and so in terms of registration are increasingly blue. However, given their built-in margins for Republicans, they look to be solidly Republican in 2020 except at the outside of a massive Biden landslide.
But while Biden may be favoured to win in 2020 given the year’s unique circumstances, the state continues to trend Republican in the short-term. Democrats appear to be consolidating their gains in the Philadelphia suburbs, but across the state Republicans are registering more new voters than Democrats. Coupled with a white, aging population with relatively low rates of bachelor-degree level education, those two factors would point to a Trump margin in a normal 2020 larger than his 2016 squeaker.
This is Trumpsylvania, a reliably Republican—though certainly far from uncontested—vote in the Electoral College with a politically ascendant whiter, less university educated, aging population increasingly in the majority. Republicans with culturally conservative policies, nativist immigration and citizenship policies, and protectionist trade policies with a splash of populist largesse will likely do well in the state.
That all looks good, or would in a normal election, for Republicans in 2020. But what about the longer term? Can Trumpsylvania survive? Well to answer that we need to look at Pennsylvania’s demographic future. The state continues to grow, but at a slower rate than the rest of the United States. That population growth, however, is not evenly distributed across the state. If we look at the county-level growth between 2010 and 2018, we see a clear pattern.
Purple counties are where the population is growing; orange is where the population is shrinking. Almost all of the state’s population growth can be found in the southeast quadrant of the state. Philadelphia and its suburbs continue to grow as does the Lehigh Valley and south central region we described above. We also see a high rate of growth in Centre County, home to Pennsylvania State University. In the western half of the state, only Butler County, home to some of Pittsburgh’s northern suburbs and exurbs, has shown any positive growth.
This means that as of 2019, only 20 of the state’s 67 counties are growing. What does this mean for the future of Trumpsylvania? In 2016, only 8 of those 20 counties voted for Hillary Clinton. But, what about 2020 and the future? Well if we use that map to divide the state into growing and shrinking counties, we can return to the 2020 county party registration numbers that showed us a 720,000 voter advantage for Democrats.
When we look at the geographic distribution of that advantage, we can see the state’s future population growth is concentrated in areas of the state that have nearly ¾ of a million more Democrats than Republicans. In most of those counties, the Republicans are losing registered voters. Where Democrats do not enjoy the advantage, for example in South Central Pennsylvania, most counties are trending towards a more Democratic-leaning population. Of course both Southwest and Northeast Pennsylvania show us just having a Democratic registration advantage does not mean the county will vote Democratic. However, the older, whiter population of Pennsyltucky, the Southwest, and Northeast will eventually age to the point at which voting is no longer possible. Republicans will then need to find a way to appeal to the growing, younger, more diverse, higher educated populations in the southeast quadrant of the state.
Pennsylvania’s political geography has changed significantly in the last 20 years, and Donald Trump’s election four years ago accelerated some of those changes in the Commonwealth. The cities of Philadelphia and Pittsburgh remain Democratic strongholds with little likelihood of flipping anytime soon. Similarly, Pennsyltucky remains a deep and unalterable shade of crimson outside of Centre County, which might turn red in 2020 due to the pandemic’s effect on university voting populations.
In the Southwest, a bulwark of Democratic support since the 1970s, the Republican transformation has all but entirely taken hold. The Democrats’ blue wall in this part of the state has all but crumbled into the sea. Erie, a 2016 Republican scalp, may revert to a Democratic bastion in 2020 and beyond, but it leans Republican long-term. These crimson hued counties will likely remain that colour for some time.
In the Northeast, Democrats in the region’s big cities of Allentown, Scranton, and Bethlehem continue to fight the rightward drift. The failure of Republicans to drastically alter Democrats’ party registration advantage between 2000 and 2016 signals the Republican takeover here is not as complete as in the Southwest. But the new 2020 registration data hints the rightward sea change may be unstoppable as the region’s demographics remain the target demographic for Trump’s Republican Party.
The Democrats have long hoped that the counter to those red waves washing over the state’s Northeast and Southwest would be countered by an ever-larger blue wall extending out and around Philadelphia’s suburbs. To their credit, Democrats managed to sweep all four counties in 2016. But those victories were by far smaller margins than those enjoyed by Republicans elsewhere in the state. The Democratic transformation here clearly is real, but it is also happening far more slowly than the Republican transformations elsewhere.
In a normal election year, Pennsylvania increasingly leans Republican and Trump probably wins reelection by a larger margin than he enjoyed in 2016. A new Trumpsylvania finally emerges and begins to remake the Electoral College map. After 2020, in the timeframe of possibly 2024 and maybe 2028, South Central Pennsylvania’s Berks, Cumberland, Dauphin, and Lancaster counties present Democrats with real opportunities for growth. They are not just growing and growing fast, at least by Pennsylvania’s standards, but they are also shedding Republican voters, though, as with Philadelphia’s suburbs, not as fast as the Southwest and Northeast are gaining Republicans.
With the population growing in the Democratic-leaning southeast and south central counties and shrinking in Republican-leaning counties in the southwest, northeast, and Pennsyltucky, a more distant reversal of the tide to a Democratic-leaning state is not out of the question. Pennsylvania may be in the middle of a red sea change, but the state’s long-term demographic trends mean it will likely only ever be a reddish purple before ebbing back to a bluish purple in the years and decades to come.
Of course the 2020 election result could change these directions. A Trump victory would likely keep the Republican Party on its current trajectory with its current base. A narrow Trump defeat would signal to Republican leaders that they could win with a more capable leader in a non-pandemic year. However, a large Biden victory could shatter the Republican Party. Trump’s base, whilst strong in Pennsylvania, continues to shrink across the nation. And after the Census Bureau tabulates the result of the 2020 Census, Pennsylvania will likely lose some electoral college votes to faster-growing and more diverse states. Republicans may need to engage in a longer-term political realignment, the outcome of which would be difficult to predict at this point. 
I want to thank all the people who let me bounce concepts, ideas, and drafts off them. I also want to thank the people who took the time to edit this piece. All the errors—factual, grammatical, or otherwise—are mine and not theirs.